Donald Trump Jr., a son of the Republican nominee for US president, in September shared an image on Instagram that includes Pepe the Frog, a crudely drawn cartoon the Anti-Defamation League has added to its database of hate symbols.

A popular Internet meme featuring a green amphibian known as "Pepe the Frog" has been added to an online database of hate symbols.

While the crudely drawn cartoon was not originally racist, it has been coopted by white supremacists and others online, according to Anti-Defamation League, which created the database in 2000 to help the public identify hate groups and their messages.

"These anti-Semites have no shame. They are abusing the image of a cartoon character, one that might at first seem appealing, to harass and spread hatred on social media," Jonathan A. Greenblatt, ADL CEO, said in a written statement.

The frog has been depicted with an Adolf Hitler-style moustache, a yarmulke, or a klansman's hood, Mr. Greenblatt noted. It is featured on the hate symbol list alongside the swastika, the Confederate battle flag, and other less apparent entries, including "100%" and "737," as The Washington Post reported.

"To the lay observer, these appear to be potential references to how much of a bottle of juice is made from actual fruit or what the make of a particular airplane is, but they’re references to white supremacist ideas – '100%' means '100% white' and '737' refers to a California-based white supremacists gang," the Post's Travis Andrews explained.

Even Taylor Swift's identity has been coopted by white supremacists who refer to her as an "Aryan goddess," according to the ADL's database.

With the rise of the alt-right – a movement with roots that can be traced back to the antebellum South, as The Christian Science Monitor's Patrik Jonsson wrote last month – the number of Pepe memes has grown as well. The current presidential election has made matters worse, according to the ADL database.

"The majority of uses of Pepe the Frog have been, and continue to be, non-bigoted," the database states, urging the public to consider each message in its context.

The announcement comes after NBC News described the frog as a "popular white nationalist symbol" that Donald Trump Jr., a son of the Republican nominee for US president, shared on social media earlier this month. Democratic candidate Hillary Clinton then posted an explainer on her campaign website to accuse her opponent, Donald Trump, of strengthening his ties to white supremacy.

"Trump has been slow to disavow support from Ku Klux Klansmen and white supremacy groups," Mrs. Clinton's campaign wrote, adding that the GOP candidate's new campaign chief, Steve Bannon, had led a Breitbart news organization cozy with the alt-right.

It has been more than a decade since cartoonist Matt Furie originally drew the frog character in the series "Boy's Club" and about eight years since the creature found new life online, as The Guardian reported. Anonymous users of the website 4Chan remixed Mr. Furie's cartoon and placed his character in various situations, oftentimes with the phrase "feels good man," the punchline from Furie's comic.

Furie told the Post he hopes Pepe's racism isn't permanent.

“I think he’s on a weird manifestation right now,” Furie said, “It’s unfortunate that he’s peaking nationally in the news in this really negative way, but I think it’s just a phase.”

“Ultimately, I hope Pepe will live on as a symbol of peacefulness and of being a cool, chill frog that kids like to share with each other on the Internet,” Furie added.